Blades

Abstract

A rotary blade, such as a turbine blade for a gas turbine engine, has an aerofoil portion with a tip partly shrouded by winglets. A gutter extends across the radially outer face of the tip to leave upstands. Cooling air feed galleries are drilled into each upstand, from the trailing edge, toward the upper end of a cooling air feed void, which is spaced from the trailing edge. Cooling passages are drilled from the winglet edges to the gallery. Cooling air supplied through the void passes along the gallery, through the passages and leaves the blade at the cooling holes. This allows cooling to be provided near the trailing edge of the tip without requiring the geometry around the trailing edge to be thickened to accommodate a cooling air void.

1 . A rotor blade comprising:
 an aerofoil portion which extends radially to a tip;   a winglet at the tip and projecting transversely, to a winglet edge, to shroud the tip;   a gutter extending across the radially outer face of the tip;   the winglet providing an upstand between the winglet edge and the gutter;   and the blade further comprising a cooling air feed gallery and at least one cooling passage extending from the feed gallery to a cooling hole at an outer surface of the blade;   wherein the feed gallery is defined, at least in part, within the upstand.   
   
   
       2 . A blade according to  claim 1 , wherein the feed gallery is defined substantially wholly within the upstand. 
   
   
       3 . A blade according to  claim 1 , wherein the feed gallery extends within the upstand, alongside the gutter. 
   
   
       4 . A blade according to  claim 1 , wherein the feed gallery is straight. 
   
   
       5 . A blade according to  claim 1 , wherein the feed gallery has substantially uniform cross-section. 
   
   
       6 . A blade according to  claim 1 , wherein the feed gallery extends to the trailing edge of the blade. 
   
   
       7 . A blade according to  claim 6 , wherein the feed gallery is closed at the trailing edge. 
   
   
       8 . A blade according to  claim 1 , wherein the feed gallery communicates with a void within the blade, to receive cooling air, in use, from the void. 
   
   
       9 . A blade according to  claim 8 , wherein the void is spaced from the trailing edge of the blade. 
   
   
       10 . A blade according to  claim 8 , wherein the void extends generally radially through the blade, toward the tip, and into the upstand. 
   
   
       11 . A blade according to  claim 1 , wherein the or each cooling passage is substantially straight. 
   
   
       12 . A blade according to  claim 1 , wherein the or each cooling passage is narrower than the feed gallery. 
   
   
       13 . A blade according to  claim 1 , wherein at least one cooling passage extends to a cooling hole in the winglet edge. 
   
   
       14 . A blade according to  claim 1 , wherein cooling air from the feed gallery is supplied to at least one cooling hole at the trailing edge of the blade. 
   
   
       15 . A blade according to  claim 1 , wherein the blade comprises winglets extending from the pressure face and the suction face of the blade, to provide respective upstands between the gutter and respective winglet edges, there being feed galleries, as aforesaid, defined, at least in part, within each upstand. 
   
   
       16 . A method of manufacturing a rotor blade, in which:
 an aerofoil portion is provided, extending radially to a tip;   a winglet is provided at the tip and projecting transversely, to a winglet edge, to shroud the tip;   a gutter is provided across the radially outer face of the tip, so that the winglet provides an upstand between the winglet edge and the gutter;   and a cooling air feed gallery and at least one cooling passage are provided within the blade, the or each cooling passage extending from the feed gallery to a cooling hole at an outer surface of the blade;   and wherein the feed gallery is formed, at least in part, within the upstand.   
   
   
       17 . A method according to  claim 16 , wherein the feed gallery is formed substantially wholly within the upstand. 
   
   
       18 . A method according to  claim 16 , wherein the feed gallery is formed to extend within the upstand, alongside the gutter. 
   
   
       19 . A method according to  claim 16 , wherein the feed gallery is formed to be straight. 
   
   
       20 . A method according to  claim 16 , wherein the feed gallery is formed to have substantially uniform cross-section. 
   
   
       21 . A method according to  claim 16 , wherein the feed gallery is formed by drilling. 
   
   
       22 . A method according to  claim 16 , wherein the feed gallery extends to the trailing edge of the blade. 
   
   
       23 . A method according to  claim 22 , wherein the feed gallery is closed at the trailing edge. 
   
   
       24 . A method according to  claim 16 , wherein the feed gallery communicates with a void within the blade, to receive cooling air, in use, from the void. 
   
   
       25 . A method according to  claim 24 , wherein the void is spaced from the trailing edge of the blade. 
   
   
       26 . A method according to  claim 24 , wherein the void extends generally radially through the blade, toward the tip, and into the upstand. 
   
   
       27 . A method according to  claim 24 , wherein the void is cast into the blade, when the blade is formed. 
   
   
       28 . A method according to  claim 16 , wherein the or each cooling passage is substantially straight. 
   
   
       29 . A method according to  claim 16 , wherein the or each cooling passage is formed by drilling. 
   
   
       30 . A method according to  claim 16 , wherein the or each cooling passage is narrower than the feed gallery. 
   
   
       31 . A method according to  claim 16 , wherein at least one cooling passage extends to a cooling hole in the winglet edge. 
   
   
       32 . A method according to  claim 16 , wherein cooling air from the feed gallery is supplied to at least one cooling hole at the trailing edge of the blade. 
   
   
       33 . A method according to  claim 16 , wherein the blade is provided with winglets extending from the pressure face and the suction face of the blade, to provide respective upstands between the gutter and respective winglet edges, feed galleries, as aforesaid, being provided, at least in part, within each upstand.